Transman robots are primarily used for handling letters after they have been
sorted into plastic trays by letter sorting machines. The plastic trays are
labelled with bar codes that contain information about the addresses of the
post in each tray. With the aid of the bar codes the Transman robots then sort
the trays and stack them in special carriages. These carriages are then loaded
manually onto trains or lorries for further transportation to the sorting centres
nearest to the addresses in question.
At these sorting centres the trays are quite often resorted so that each carriage can be refilled with even more precisely sorted post.
A gantry robot is used when the trolleys are unloaded for resorting and the final loading of the carriage is also carried out using a similar type of robot.